Now it’s obvious what she wants to do — let the music lead her life, she said from a rehearsal in Los Angeles.

Doubt evaporated after praise from critics and fellow musicians like Pat Metheny, and two invitations to perform at the White House. There’s nothing more reassuring than playing a song, then seeing the President smiling broadly in the audience.

“It was awesome, man!” the 24-year-old bassist / vocalist said about playing for President Barack Obama this year. “It was a blessing, really inspiring to be in there to play music.”

She performed as part of a Stevie Wonder tribute in February, then as part of a spoken-word and jazz program in May. “I met him (Obama), and it was really cool. It was a blessing to meet someone like that outside of their politicking, you know.”

Spalding was also excited to back Tony Bennett at the February set. “He’s so beautiful! People like him, people like Wayne Shorter, Milton Nascimento, it’s like they are just here for the music. ... Free from pretension and, free from trying to presuppose what people want. I just hope to be one of those contributors one day.”

Road to White House

With a single mother who encouraged her musical talents, Spalding grew up in a poor part of Portland, Ore. Due to illness, she was home-schooled for much of her childhood. “I spent days, weeks and months just alone, I wouldn’t see anyone else my age.” Sometimes she’d wander the neighborhood. “I’d be the kid who’d show up at a store at 11 a.m. People would be like, ‘Aren’t you supposed to be in school?’”

Spalding learned self-discipline, and would practice music on the violin constantly. But she got frustrated with organized learning. In public school, she’d think: “These people don’t know what I can do. ... People trying to tell you how to do something. I remember being in elementary school thinking: ‘Let me just take some time to figure it out!’” She wanted to learn things and do things her own way.

She won a scholarship to a performing-arts high school. There, she happened to pick up and mess with an acoustic bass. The music instructor caught her. But instead of meting out punishment, he taught her a basic blues line. Just 14, she used that to get her first gig in a blues band, and she was hooked. A scholarship to Berklee followed.

In the prestigious Boston college, Spalding met a lot of professional jazz musicians who “scared” her into being serious about the music.

At age 19, she met Metheny, who asked what she wanted to do. “I didn’t know if I wanted to do music, because it was sort of oppressive where I was at this school,” she said. “I don’t know if this is the best use of my time and my creative talents, maybe I should go study something else, maybe try to be more of a player, more hands-on and improving people’s lives who are impoverished or suffering,” she told Metheny.

“In a very nonchalant way, he said: ‘You know, I meet a lot of people and I bet if you really applied yourself your potential would be limitless.’ It was what I needed to hear to keep me going.”

Music ‘as a bridge’

In a 2008 interview with the Christian Science Monitor, Metheny said it was obvious “that she had a lot to say and was also unlike any musician I had ever run across before. Her unique quality is something that goes beyond her pretty amazing musical skills; she has that rare ‘x’ factor of being able to transmit a certain personal kind of vision and energy that is all her own.”

Spalding is unique in being a jazz bassist / vocalist. There have been famous jazz bassists, like Charles Mingus, Jaco Pastoriuscq and Slam Stewartcq, but many times the bassist tends to be the person in the background. “Sonically, it doesn’t cut through like other instruments do,” she said.

But in her sets, “most of the lead is being covered by the voice. I really think of it like a piano,” she added. Like the right and left hand on the keys, her voice takes care of the melody, while her bass is dancing around underneath. “I feel like one instrument when I play.”

In a review of her second album, “Esperanza” (2008, Heads Up), the Boston Globe wrote: “As a bassist and bandleader, Spalding has a knack for pushing the instrument’s range and cultivating its melodic possibilities, and her seemingly equal command of three jazz vernaculars — straight-ahead, Latin and Brazilian — makes for a program that’s diverse yet flows with ease and coherence.” But the review notes that her smooth vocals make it “a more accessible album, and in some ways more conventional.”

She has a voice that could be on the non-jazz charts, which brings up the delicate subject, for hardcore jazz fans, anyway, of crossover.

Spalding would be happy if she got a larger mass audience, she said. “I will crossover, I’m sure. It doesn’t mean that my music will crossover. My music already does serve as a bridge between mainstream and artistic commitment ... But the only master I’m serving is the music. I think that when listeners get frustrated or disappointed with an artist is when they feel like they’ve started serving the masses or serving marketability or what they think the media wants.”

Her music could appeal to a mass audience, “not because that’s my objective, but that’s how the music sounds,” she explained. She hopes it appeals to jazz fans “and to people who just want to groove and enjoy some nice songs. And if that doesn’t happen, that’s OK, too, because I know the music won’t let me down.”